Method of determining temperatures in metal-working



' 0. c. GlLBERT.

METHOD OF DETERMINING TEMPERATURES IN METAL WORKING. APPLICATION FILED mm 21,. 1919.

79,909. Patented May 31, 1921;

/n en f0) O/iver 61 Gilber' 7.

by Ark}.

To all whom. it may concern:

.omvn'n o. GILBERT, or new YORK, .N. ,Y.

METHOD or DETERMINING marina-arenas Iii METAL-WORKING.

Application filed June 21, 1919. Serial No. 305,756.

Be it known that I, OLIVER O. GILBERT, a

citizen of the United States, residing at' New 'York, in the county of New York,

State of New York, have invented certain new and usefullmprovements in Methods of Determining Temperatures in Metalworking, of which the following is a full,

clear, concise, and exact description.

This invention relates to a method of. determining the temperature to which metals and their alloys are" heated in passing through a die.

The drawing of metals and their alloys through a die, due to the friction between. the metal and die as well as fluid friction within the metal during the reduction, heats both metal and die to a high temperature,

the degree thereof depending upon the amount of reduction, the hardness of the metal, and the speed at which the metal passes through the die as well as upon the 7 condition of the die itself. In the commercial drawing'of metals it is desirable to attain the greatest speed possible in a given reduction without injuring the metal. To permit of high speed in drawing the metal through'the die, in practice, .a lubricant 15 applied to the metal and 'die to lower the.

temperature of both sufliciently to prevent injury to the metal and at times the operation is conducted under water to ofi'set'heating. Wherea lubricant is vused efficiently, only enough is employed to keep the metal and die at the desired temperature. Hereto- -fore, the temperature of the lubricant necessary in any given reduction process has been determined by continued experiment both in process.

the application of lubricants of difierent temperatures and also in the speed of reduction. Such a method is slow'a-ndcalso expen sive, slnce the metal that 1s annealed or overdrawn must be discarded but has been necessary due to the difliculty of ascertaining the effect of the drawing during the reduction Metal thatihasbeen drawn througha die has a dissimilar physical state from'the undrawn metal, the molecules of'the former being dissimilarly oriented, whereby it pos-" sesses greater tensile strength. Since the drawn and undrawn metals. are dissimilar in physical characteristics andsince'at the point of reduction, or in other words, with- The present plates the use-of this thermo-couple in the galvanometer may in the die, heat of high temperature generated due to the reduction, a thermo-couple Specification of Letters Patent. I Patented lIay 1921,

isformed between the drawn and undrawnmetal.

usual manner by-applying the brushes of a delicate galv'anometer to the metal just beimproved method contenil fore and after it leaves the die, as' is illus trated in the accompanying drawing, Figures 1 and 2 thereof being diagrammatic illustrations showing the'several steps of the method, 1 representing thelgalvano'meter,

the brushes2 and 3 of whichare'applied to the metal'just be'foreand after'it leaves the d e 4.#During the-reduction of the metal,

the thermop-ile previously described will generate a thermo-electromotive force or current which will be'measured' or'ilidicated "f on the galvanometer. I speed of reduction has been reached the reading of the galvanometer is' noted and the reduction of the metal'is stopped. I The section of the metal extending from a point beyond the brush 2 to a point beyond the brush 3, as indicated by the dotted lines 5,

is then c'utfrom the body of theimetal and withdrawn frbm the die. This section of When the desired p metal is bent into auv-shapef'and then im-' mersed in a tank 6 containing oil,the ends .o'f the metal, however, protruding beyond the oilgand with the brushe's'2 and 3 ofthe galvanometer attached thereto at thesame points as they occupied'during'the reduction. 1

The oil in the tank isthen heatedby Bunsen burner, or other suitable means,

until the galvanometer registers the same reading as the one previously noted. In

this instance the thermo-electrornotive force isgenerated due to the same d1ss1m1lar physcal characteristics in the sectlongof metal,

the heat of the oil serving inlieu of the 1 heat caused by the friction'of the die. A thermometer 8 immersed in the oil bath during the heating of the oil will indicate the temperature of the metal for the given "galvanometer reading, In this; manner a be calibrated for any given'metal; i p 7 Knowing the temperatures indicated by the various readings ofthe galvanometer for agiven-metal, any desired temperature of the metal} during reduction maybe had by applying a refrigerant and regulating the ing on the galvanometer.

speed of reduction until the desired temperature is indicated by its corresponding read- What is claimed is: g V 1. The method of determiningthe temperature of a metalor alloy as it passes through a die, which involves a measurement dependent upon a movement of the metal or alloy and proportional to the electromotive force developed by the thermocouple formed by the drawn and undrawn metal or alloy While it is passing through the die.

' 2. The method of determining the tem perature of a metal or alloy as'it passes through a die, consisting in measuring the :thermo-electromotive force generated by the passage of the metal or alloy through the die in a given reduction, heating the metal or alloy after it has been partly passed through the die in a fluid until the same measured 'thermo-electromotive force is attained, and simultaneously measuring the temperature of the said fluid.

. 3. The method of determining the tem perature of a metal or alloy as it passes through a die, consisting in measuring the electrical effect produced by the thermocouple formed by the drawn and undrawn metal or alloy and comparing this efiect with that'produ'ced by the same couple at known temperatures. Y

l. The method of determining the temperature of a metal or alloy as it passes through a die consisting in applying'the brushes of a galvanometer to the metal or alloy'just before and just after it leaves the die, noting the reading vof the galvanometer for any given reduction, cutting .fromthe body of the metal or alloy a section which comprises a dravvn portion and an undrawnportion, immersing the section of metalor alloy in a fluid With'the galvanometer brushes attached, heating the fluid until the'previously noted reading of the galvanometer is attained, and immersing a thermometer in the fluid to measure the temperature thereof.

'5. The method of determining the temperature of a metal oralloy as it passes through a die consisting in applying the brushes of a galvanometer to the metal or alloy just before and just after it leaves the die, noting the reading of the galvanolneter for any given reduction, cutting from the body of the metal or alloyavseclilOIL-WhlC-l'l comprises a drawn portlonand an und-rawn portion, immersing the section of metal or alloy in a fiuidqwith portions die, notingithe readingof the galvanometer for any given reduction, cutting from the body of the metal or'alloy a section comprising a drawnportion and an undrawn p0rtion, bending the section into a U-shape'and immersing it in a fluid With portions projecting beyond the same, applying the brushes of the galvanometer to the projecting portions of the metal or alloy, heating the fluid until the previously noted reading of the galvanometer is attained, and simult'aneously measuring the temperature of the said fluid. a

p In Witness whereof, I hereunto subscribe my name this 19th day of June A. D., 1919.

, OLIVER o. GILBERT. 

